Potassium bis(trimethylsilyl)amide → tert-butyl N-(3-methylidenecyclobutyl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a three necked flask equipped with additional funnel which was cooled to −78° C. was added a solution of methyl(triphenyl)phosphonium bromide (43 g, 121 mmol) in anhydrous tetrahydrofuran (200 mL) under nitrogen protection. 1 M KHMDS in tetrahydrofuran (105 mL, 105 mmol) was then introduced dropwise over 40 minutes while the internal temperature was kept below −60° C. After addition, the mixture was stirred at −78° C. for 15 minutes. Then a solution of tert-butyl(3-oxocyclobutyl)carbamate (14 g, 81 mmol) in 100 mL of tetrahydrofuran was added slowly while the internal temperature was kept below −60° C. The resulting mixture was then warmed naturally to room temperature and stirred overnight. The resulting reaction mixture was diluted with EtOAc, and then washed with saturated aqueous solution of ammonium chloride and brine, then dried over anhydrous Na2SO4 and then concentrated in vacuo. The residue was purified by flash chromatography (EA:PE=1:10 to 1:2) to afford tert-butyl(3-methylidenecyclobutyl)carbamate (7.5 g).

Provenance & Evidence